The above-mentioned scanner heads are used for various purposes, in particular for marking, labeling, for abrasive and/or structuring processing, for cutting, for drilling, for sintering, or for welding. For various applications of laser material processing, it is advantageous not only to guide the position of the laser focus on an arbitrary path, but at the same time to control the angle of incidence of the laser beam axis on the workpiece. As a result, structures of any shape (for example) can be introduced into a workpiece, the edges of which feature a desired angle of inclination to the workpiece surface. Ideally, the angle of incidence should be adjustable independently of the path guidance. The independent adjustment of both parameters should be feasible with high precision and high speed, in order to achieve correspondingly high processing speeds in laser material processing.
A corresponding device and a method for guiding a laser beam is known from DE 10 2013 222 834 A1. The device for guiding the laser beam for machining a workpiece features a mirror device with movable mirrors for generating an angle of attack of the laser beam on focusing optics for adjusting a lateral offset of the laser beam on the workpiece and for generating a lateral offset of the laser beam on the focusing optics for adjusting an angle of incidence of the laser beam on the workpiece. Along the propagation of a laser beam, a first beam splitter is arranged between a laser source and the mirror device. A first sensor element is allocated to the first beam splitter. Such first sensor element serves to monitor the beam profile and the beam position. Thereby, the beam position can be detected exclusively in an area upstream of the mirror device. The disadvantage here is that an adjustment of the system can take place exclusively through components that are upstream of the mirror assembly in the direction of propagation of the laser beam. Usually, these are components are not parts of the scanner head. Such an adjustment is highly complex, protracted, and expensive.
Furthermore, DE 10 2004 053 298 A1 discloses a scan head as part of a laser, drilling and cutting device. This features a series of the following components arranged in the light path of the laser: an intensity-regulating beam damping unit in conjunction with a wobble unit regulating a parallel beam displacement, a beam expander telescope increasing the beam cross section of the laser, a scan block guiding the focus of the laser beam, and a working unit focusing the laser beam on the specimen along with additional testing and control units that optionally can be coupled in the light path. The beam damping unit contains a sequence, arranged in the light path, of a retarder, a first Brewster window and a second Brewster window, whereas the retarder and/or at least one of the two Brewster windows are designed to be rotatable around the optical axis. The wobble unit is formed from arrangement of two plane-parallel windows introduced into the light path, whereas the axis of rotation of the first plane-parallel window, the axis of rotation of the second plane-parallel window, and the direction of propagation of the laser beam are orthogonal to each other. The retarder or the plane-parallel window are expediently moved by galvanometer units.